As the advances in science, technology, and the improvement in quality of life, people have higher and higher standards for lighting using LED lamps. To realize second time energy conservation, people expect to realize brightness adjustment by freely adjusting the brightness of lamps. To create different moods/atmosphere, people are desire to adjust color temperature of LED lamps and personalize light ambient.
It has been found that, by using two dimming power supplies to respectively drive white LED arrays of two color temperatures, i.e., a high color temperature and a low color temperature, and adjusting a ratio of driving current in the two dimming power supplies, color temperature adjustment may be implemented. However, the described conventional method of color temperature adjustment often causes problems. For example, adjustment of brightness often affects adjustment of color temperature. People often do not like the brightness of the lamp to change when adjusting the color temperature of the lamp, or the color temperature of the lamp to undergo substantial shift when adjusting the brightness of the lamp. That is, people often prefer little or no interference between color-temperature adjustment and brightness adjustment.
The disclosed devices and methods are directed to solve one or more problems set forth above and other problems.